#!/usr/bin/env python
#coding: utf-8

class Handler(object):
    '''
    '''

    def callback(self, perfix, name, *args):
        method = getattr(self, perfix + name, None)
        if callable(method):
            return method(*args)

    def start(self, name):
        self.callback('start_', name)

    def end(self, name):
        self.callback('end_', name)

    def sub(self, name):
        def substitution(match):
            result = self.callback('sub_', name, match)
            if result is None: match.group(0)
            return result

        return substitution


class HTMLRenderer(Handler):
    '''

    '''
    def start_document(self):
        print '<html><head><title>...</title></head><body>'
    def end_document(self):
        print '</body></html>'
    def start_paragraph(self):
        print '<p>'
    def end_paragraph(self):
        print '</p>'
    def start_heading(self):
        print '<h2>'
    def end_heading(self):
        print '</h2>'
    def start_list(self):
        print '<ul>'
    def end_list(self):
        print '</ul>'
    def start_listitem(self):
        print '<li>'
    def end_listitem(self):
        print '</li>'
    def start_title(self):
        print '<h1>'
    def end_title(self):
        print '</h1>'
    def sub_emphasis(self, match):
        return '<em>%s</em>' % match.group(1)
    def sub_url(self,  match):
        return '<a href="%s">%s</a>' % (match.group(1),match.group(1))
    def sub_mail(self,  match):
        return '<a href="mailto:%s">%s</a>' % (match.group(1),match.group(1))
    def feed(self, data):
        print data